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-rw-r--r--login/Makefile16
-rw-r--r--login/forkpty.c56
-rw-r--r--login/openpty.c73
-rw-r--r--login/programs/pt_chown.c88
-rw-r--r--login/pty-internal.h41
-rw-r--r--login/utmp_file.c10
6 files changed, 275 insertions, 9 deletions
diff --git a/login/Makefile b/login/Makefile
index 3842b2f4af..04c6eeb8a4 100644
--- a/login/Makefile
+++ b/login/Makefile
@@ -1,4 +1,4 @@
-# Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+# Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
 # This file is part of the GNU C Library.
 
 # The GNU C Library is free software; you can redistribute it and/or
@@ -25,10 +25,14 @@ subdir	:= login
 headers	:= utmp.h bits/utmp.h utmpx.h bits/utmpx.h lastlog.h pty.h
 
 routines := getutent getutent_r getutid getutline getutid_r getutline_r \
-	    utmp_file utmp_daemon utmpname updwtmp
+	    utmp_file utmp_daemon utmpname updwtmp \
+	    getpt grantpt unlockpt ptsname
 
-others = utmpd utmpdump
+CFLAGS-grantpt.c = -DLIBEXECDIR='"$(libexecdir)"'
+
+others = utmpd utmpdump pt_chown
 install-sbin = utmpd
+install-others = $(inst_libexecdir)/pt_chown
 utmpd-routines := connection database error request xtmp
 extra-objs := $(utmpd-routines:=.o)
 
@@ -42,11 +46,15 @@ vpath %.c programs
 extra-libs      := libutil
 extra-libs-others := $(extra-libs)
 
-libutil-routines:= login login_tty logout logwtmp pty
+libutil-routines:= login login_tty logout logwtmp openpty forkpty
 libutil-map	:= libutil.map
 
 include ../Rules
 
+# pt_chown needs to be setuid root.
+$(inst_libexecdir)/pt_chown: $(objpfx)pt_chown
+	$(INSTALL) -m 4755 -o root $< $@
+
 $(objpfx)utmpd: $(utmpd-routines:%=$(objpfx)%.o)
 
 # Depend on libc.so so a DT_NEEDED is generated in the shared objects.
diff --git a/login/forkpty.c b/login/forkpty.c
new file mode 100644
index 0000000000..e0e3cce9f9
--- /dev/null
+++ b/login/forkpty.c
@@ -0,0 +1,56 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <sys/types.h>
+#include <termios.h>
+#include <unistd.h>
+#include <utmp.h>
+#include <pty.h>
+
+int
+forkpty (amaster, name, termp, winp)
+     int *amaster;
+     char *name;
+     struct termios *termp;
+     struct winsize *winp;
+{
+  int master, slave, pid;
+
+  if (openpty (&master, &slave, name, termp, winp) == -1)
+    return -1;
+
+  switch (pid = fork ())
+    {
+    case -1:
+      return -1;
+    case 0:
+      /* Child.  */
+      close (master);
+      if (login_tty (slave))
+	_exit (1);
+
+      return 0;
+    default:
+      /* Parent.  */
+      *amaster = master;
+      close (slave);
+
+      return pid;
+    }
+}
diff --git a/login/openpty.c b/login/openpty.c
new file mode 100644
index 0000000000..12e82072bc
--- /dev/null
+++ b/login/openpty.c
@@ -0,0 +1,73 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <fcntl.h>
+#include <pty.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include "pty-internal.h"
+
+int
+openpty (pmast, pslave, pname, tio, wins)
+     int *pmast;
+     int *pslave;
+     char *pname;
+     struct termios *tio;
+     struct winsize *wins;
+{
+  int pfd, tfd;
+  char name[PTYNAMELEN];
+
+  pfd = getpt ();
+  if (pfd == -1)
+    return -1;
+
+  if (grantpt (pfd))
+    goto bail;
+
+  if (unlockpt (pfd))
+    goto bail;
+
+  if (!ptsname_r (pfd, name, PTYNAMELEN))
+    goto bail;
+
+  tfd = open (name, O_RDWR);
+  if (tfd == -1)
+    goto bail;
+
+  /* XXX Should we ignore errors here?  */
+  if(tio)
+    tcsetattr (tfd, TCSAFLUSH, tio);
+  if (wins)
+    ioctl (tfd, TIOCSWINSZ, wins);
+
+  *pmast = pfd;
+  *pslave = tfd;
+  if (pname != NULL)
+    strcpy (pname, name);
+  return 0;
+
+bail:
+  close (pfd);
+  return -1;
+}
diff --git a/login/programs/pt_chown.c b/login/programs/pt_chown.c
new file mode 100644
index 0000000000..dbf79fc6ad
--- /dev/null
+++ b/login/programs/pt_chown.c
@@ -0,0 +1,88 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by C. Scott Ananian <cananian@alumni.princeton.edu>, 1998.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* pt_chmod.c ... securely implement grantpt in user-land.  */
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
+#include <grp.h>
+
+#include "pty-internal.h"
+#define Str(x) _Str(x)
+#define _Str(x) #x
+
+void
+usage (void)
+{
+  fprintf (stderr, _("usage: pt_chown FD>&%s\n"
+		     "This program is used internally by grantpt(3).\n"),
+	   Str (PTY_FD));
+  exit (0);
+}
+
+void
+bad_installation (void)
+{
+  fputs (_("pt_chown: installation problem: "
+	   "This program needs to be setuid root.\n"), stderr);
+  exit (FAIL_EXEC);
+}
+
+int
+main (int argc, char **argv)
+{
+  struct group *grp;
+  struct stat s;
+  char *pty;
+  gid_t gid;
+  uid_t uid;
+
+  if (argc != 1)
+    usage ();
+  if (geteuid () != 0)
+    bad_installation ();
+
+  grp = getgrnam (TTY_GROUP);
+  gid = grp ? grp->gr_gid : getgid ();
+  uid = getuid ();
+
+  /* Check that fd is a valid pty master -- call ptsname().  */
+  pty = ptsname (PTY_FD);
+  if (pty == NULL)
+    return errno == EBADF ? FAIL_EBADF : FAIL_EINVAL;
+  close (PTY_FD);
+
+  /* Check that target file is a character device.  */
+  if (stat (pty, &s))
+    return FAIL_EINVAL; /* This should only fail if pty doesn't exist.  */
+  if (!S_ISCHR (s.st_mode))
+    return FAIL_EINVAL;
+
+  if (chmod (pty, 0620))
+    return FAIL_EACCES;  /* XXX: Probably not true. */
+
+  if (chown (pty, uid, gid))
+    return FAIL_EACCES;
+
+  return 0;
+}
diff --git a/login/pty-internal.h b/login/pty-internal.h
new file mode 100644
index 0000000000..c1858861ec
--- /dev/null
+++ b/login/pty-internal.h
@@ -0,0 +1,41 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* Internal constants used by the pseudoterminal handling code. */
+
+#ifndef _PTY_INTERNAL_H
+#define _PTY_INTERNAL_H	1
+
+/* Length of a buffer to hold a pty name. */
+#define PTYNAMELEN 15   /* "/dev/pts/65535$" */
+
+/* Which group should pty slaves belong to: */
+#define TTY_GROUP "tty"
+
+/* Communication between grantpt and pt_chown. */
+#define PTY_FD 3
+enum  /* failure modes */
+{
+  FAIL_EBADF = 1,
+  FAIL_EINVAL,
+  FAIL_EACCES,
+  FAIL_EXEC
+};
+
+#endif
diff --git a/login/utmp_file.c b/login/utmp_file.c
index bea63644f7..d25dcb8600 100644
--- a/login/utmp_file.c
+++ b/login/utmp_file.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+/* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>
    and Paul Janzen <pcj@primenet.com>, 1996.
@@ -390,12 +390,12 @@ pututline_file (const struct utmp *data)
     }
 
   /* Write the new data.  */
-  if (write (file_fd, data, sizeof (struct utmp)) != sizeof (struct utmp)
+  if (write (file_fd, data, sizeof (struct utmp)) != sizeof (struct utmp))
+    {
       /* If we appended a new record this is only partially written.
 	 Remove it.  */
-      && found < 0)
-    {
-      (void) ftruncate (file_fd, file_offset);
+      if (found < 0)
+	(void) ftruncate (file_fd, file_offset);
       pbuf = NULL;
     }
   else